Project Summary/Abstract US rates of alcohol and drug use among youth remain problematic, and changes in youth use of opioids, marijuana, and e-cigarettes have increased the need for prevention. Evidence-based programs (EBPs) for re- ducing alcohol and drug use are not widely adopted by schools and are often implemented poorly. Although studies show that schools do have time during the school day, multiple factors influence schools? poor imple- mentation including inadequate funding, teacher turnover, lack of confidence in program evidence, insufficient support from school staff, poor alignment between programs and stated goals, and lack of technical assistance to guide good implementation. A middle-school drug prevention program called Project ALERT and imple- mentation support intervention called Getting To Outcomes (GTO) can address these factors and improve pre- vention quality and youth outcomes. ALERT is a widely implemented middle-school program that is free, has moved to all online teacher training, has been recently updated for new drug trends, and has promising evi- dence for preventing drug use and reducing pro-drug risk factors, as rated by multiple online registries. GTO is an intervention which includes training, manuals, and technical assistance that builds capacity for programs by strengthening the knowledge, attitudes, and skills needed to choose, plan, implement, evaluate, and sustain those programs. Previous studies in small community agencies have demonstrated GTO?s promise, but its im- pact on school-based prevention fidelity and youth outcomes remains an empirical question. We propose a study to assess the effectiveness of the updated ALERT in combination with an assessment of GTO implemen- tation support. The proposed 5-year study compares the effectiveness of ALERT alone, ALERT+GTO, and a no- intervention control group in a Hybrid II, cluster-randomized controlled trial of 42 middle schools across three states. As a Hybrid II trial, we will test both the effectiveness of the revised ALERT curriculum and teacher training method as well as the GTO implementation support. Although generic GTO tools are available, in this study we will tailor those tools specifically for ALERT. We will evaluate both implementation outcomes (e.g., staff capacity, program fidelity) and outcomes of substance use such as alcohol, marijuana, e-cigarette, and opi- oid use; and pro-drug risk factors such as resistance self-efficacy, perceived peer norms, and beliefs among 3,088 middle-schoolers. A successful demonstration of ALERT+GTO could fundamentally transform evidence- based prevention?s reach and quality where most youth are?US schools. That is because ALERT is an imple- mentation-friendly program (free, accessible) that is already being employed by thousands of schools and RAND would offer all the GTO support to schools for free after the study. If successful, the new ALERT?sup- ported by GTO tools and guidance tailored to ALERT?would be one of the easiest EBPs for schools to adopt or continue implementing but with improved quality.